Multi-stage rotary jacks

ABSTRACT

This invention relates to multi-stage rotary jacks, of the kind in which each stage has a vane that is capable of turning with respect to the wall of a cylindrical casing, the vane or the casing constituting, as desired, a rotor and a stator and all the stages being coaxially aligned one above the other. According to the invention, the stator and rotor members of each stage are idly mounted on a central shaft except for one of said members of an end stage and this excepted end member is keyed to the central shaft to rotate therewith but the rotor of each stage is keyed to the stator of one of its two contiguous stages so as to rotate therewith.

Unit States Patet 1 Grosseau [4 1 May 15, 1973 [54] MULTI-STAGE ROTARYJACKS References Cited [75] Inventor: Albert Grosseau, Chaville, FranceUNITED STATES PATENTS [73] Assignee: Citroen SA (Automobile Citroen,2,911,956 11/1959 Smith, Jr. ..92/67 Berliet, Panhard), Paris, France3,289,544 12/1966 Daniels ..91/167 3,289,544 12/1966 Daniels ..91/l67 A[22] Filed: May 13, 1971 Primar Examiner-Paul E. Maslousk 21 A 1. No..143,157 Y y 1 pp A ttorney-Marn &Jangarath1s Related U.S. ApplicationData [57] ABSTRACT [63] Continuation of 5 No, 310 212 March 29 19 9 Thisinvention relates to multi-stage rotary jacks, of abandoned. the kind inwhich each stage has a vane that is capable of turning with respect tothe wall of a cylindrical casing, the vane or the casing constituting,as desired, a [30] Forelgn Appllcatlon Pmmty Dam rotor and a stator andall the stages being coaxially Mar. 29, 1968 France ..68l46488 alignedone above the other.

' According to the invention, the stator and rotor mem- [52] US. Cl...92/66, 92/679,l92l/6172i, bers of each Stage are idly mounted on acentral Shaft except for one of said members of an end stage and [51]int. Cl. ..F0lb 15/00, F15b 11/18 this excepted end member is keyed tothe central Shaft [58] Field of Search ..235/201 ME;

to rotate therewith but the rotor of each stage is keyed to the statorof one of its two contiguous stages so as to rotate therewith.

8 Claims, 5 Drawing Figures ii" 5 t MULTll-STAGE ROTARY JACKS Thisapplication is a continuation of U.S. application Ser. No. 810,212 filedon Mar. 29, 1969 and now abandoned.

It is known that rotary jacks used at this time do not generally permitof rotations of less than 360 and do not possess the flexibilitysufficient to satisfy the multifarous requirements of industry.

The present invention has for an object a rotary jack having multipleelements which removes or minimizes these drawbacks and, in particular,allows a limited rotation to be obtained but, nevertheless, which is ashigh as is desired. In certain other cases, which will become apparentin the description to follow, the invention allows several successiverotations to be obtained on the same member and having a predeterminedvalue, the sum of these rotations being capable of exceeding 360.

To this end, the invention has for an object a multistage rotary jack,each stage or elementary rotary jack comprising a vane that is capableof turning with reference to the wall of a cylindrical chamber, thesetwo members indiscriminately constituting what can be referred to as therotor and the stator of the element.

According to the invention, these stages are coaxially aligned one abovethe other and their members (stator and rotor) are idly mounted on acentral'shaft with the exception of one of the members (rotor or stator)of one end stage that is itself keyed on to rotate with the centralshaft but, however, the rotor of each stage is keyed on to rotate withthe stator of one of two contiguous stages.

In accordance with another feature, the central shaft has at least onesupply channel leading into the interior of the chambers of each stage.

In order that the invention may be more clearly understood, referencewill now be made to the accompanying drawings which show two embodimentsthereof by way of example, and in which: 7

FIG. 1 shows an axial section through a four-stage rotary jack inaccordance with the the invention,

FIG. 2 shows a section along the line II-II of FIG. 1, FIG. 3 shows asection along the line III-III of FIG. 1

modification of the invention, and

FIG. shows a section along the line VV of FIG.

Referring now to the drawings, reference will first be made to FIGS. 1and 2, in which can be seen ajack that comprises four identical stagesor elements, designated by the general reference A,B,C and D. Each stageis constituted by a cylindrical casing 1 having in the interior thereofa sleeve 2 provided with a radial vane 2a which is mounted to rotateabout the axis of the casing. An abutment 3 fixed to the casing l andextending up to the sleeve 2 limits the angular movement of displacementof the vane and defines with it two chambers la and lb.

The vane and the casing respectively constitute the rotor and the statorof each stage in the embodiment herein described.

The sleeves 2 and the casings 1 of each stage are idly mounted on acentral shaft 4 by means of roller bearings. The central shaft thusensures a satisfactory alignment and centering of all the stages of thejack. The rotor 2, 2a of the upper end stage D is keyed on so as FIG. 4shows a view similar tothat of FIG. 1, of a to rotate with the shaft 4by any desired means, but the casing 1 forming the stator of the lowerend stage A is fixed to a block P constituting the lower end of thissta- As shown, the sleeve 2 is connected to the shaft 4 through anintermediate rotatable member 21, which includes a downwardly extendingfinger 22 received in a recess 23 in sleeve 2. The shaft 4 is fastenedto the rotatable member 21 by a suitable fastening means, such as screws24. In operation, rotation of sleeve 2 causes an interior surface ofrecess 23 to engage the finger 22, whereby the rotatable member 21 isrotated by the sleeve 2, the rotatable member in turn rotating the shaft4.

On the other hand, as will readily be apparent from FIG. 1, the rotor 2of the stage A passes through the upper cover of the casing of thisstage and has at its end a recess 2b cooperating with a spigot 1cprovided on the inner surface of the casing l of the contiguous stage13. The same construction is employed for the other stages, each rotorthus being keyed to rotate on the stator of one of the two contiguousstages.

Two conduits 5 and 6 are provided in the casing l of the lower end stageA, said conduits leading respectively into the chambers 1a and 1b ofthis stage. These conduits are respectively adapted to be connected to asource of fluid under pressure and discharge piping.

Two conduits 7 and 8 are provided in the sleeves 2 of each stage andthese conduits lead, on the one hand, into the chambers 1a, 1b and, onthe other hand, into circular internal necks 9 and 10. For its part, thecentral shaft 4 is provided with two bores 11 and 12, the

bore 11 having orifices 11a at the level of the necks 9 of each stage,whilst the bore 12 has orifices 12a at the level of the necks 10. Theupper ends of the bores 11 and 12 are obturated in any desired fashion.Thus, all the chambers 11: are in communication by the intermediary ofthe bore 11, and the chambers 1b by the bore 12. The operation of thecomposite jack is thus as follows. It will be supposed that the initialposition of all the vanes 2a of the stages correspond to that shown inFIG. 2, in which the vanes 20 do not touch the abutments3.

When the conduit 5 is placed in communication with the source of fluidunder pressure and the conduit 6 with the discharge piping, the fluidunder pressure passes into the chamber la of the lower stage A effectinga rotation, in the direction of arrow F (FIG. 2), of the vanes 2a whichdrive back the fluid contained in the chamber 112.

The pressure extant in the chamber of the lower stage A is transmittedto the chamber 10 of the upper stages B, C and D by conduits 7, necks 9and the bore 11, effecting the rotation of their vanes 2a with referenceto the corresponding-casing l. 7

However, with reference to the fixed casing l of the lower stage A, therotations of the various vanes 2a add together, since each stator iskeyed on the next adjacent lower rotor; the central shaft 4 keyed 0n thelast rotor 20 turns with respect to the structure through an angle equalto the sum of the rotations of each vane with respect to its casing.There is thus obtained a total rotation of the shaft which is greaterthan 360-and, in

the example described, equal to four times the maximum rotation of eachstage.

It should be stressed that the explanations given above-neglect the flowlosses which can be produced in the c'ommunications between the variousstages. It is not certain that the vanes of the four stages turnsimultaneously about the same angle; in any case, a predeterminedrotation of the shaft 4 corresponds to each quantity of fluid introducedthrough the conduit 5.

The return to the initial position represented in FIG. 2 is effected bypermuting the connections of the conduits 5 and 6.

FIGS. 4 and 5 show another embodiment of the invention, in which themembers referred to above are not described again but have been giventhe same reference numerals augmented by 100.

In this embodiment, the central shaft 104 is fixed and the stator of thelower stage A,, constituted by a sleeve 102, provided with twosymmetrical radial vanes 102a, is also fixed by downwardly extendingfingers 131 received in recesses 132 in base 133. Thus, the sleeve 102is connected to the shaft 104 through the base 133. The rotor 101carries two abutments 103 and is keyed on the lower stator of the nextadjacent upper stage B, by a suitable keying means. As shown, keying iseffected by fingers 141 on the inner surface of the. stage B, which arereceived in and cooperate with corresponding recesses 142 in the rotor101 of the stage A,. In a similar fashion, the rotor of each of theother stages is keyed on the stator of the stage immediately thereaboveand the rotor 101 of stage D, is keyed to wheel 113. At the upper partof the composite jack, the rotor, constituted by casing 101, is keyed torotate on a toothed wheel 113 cooperating with a driving member that isnot shown in the drawing. Each stage of the composite jack comprises twovanes and thus two chambers 101a and two chambers llb are present. Allthe chambers 101b communicate via a bore 112 and necks 110 and areadapted to be successively connected to discharge piping and piping forfluid under pressure.

The bores 11 1a and lllb, etc. are, on the other hand, provided on thecentral shaft and respectively communicate by necks 109 with thechambers 101a of each stage.

These bores are adapted to be selectively connected to a source of fluidunder pressure and to discharge pip- It is to be observed that, in thisembodiment, the various stages are not generally identical. MOreprecisely, the abutments 103 have different relative dimensions, thuspermitting different rotations of the rotors with reference to thecorresponding stators. The operation is thus as follows: the rotors 101are all in the position set out in FIG. and one of the bores 111, forexample, the bore lllb, is placed in communication with the source offluid under pressure. The rotor 101 of the stage B, is displaced in thedirection of the arrow F, until it comes to rest on the abutments 103 bydiminution of the chambers l0lb which drive back the fluid that theycontain, into the bore 112. In its movement, the rotor 101 of the stage8, drives the stator of the stage C which drives the corresponding rotorby the vanes resting on the abutments 103 and so on up to the rotor 101of the upper end stage keyed on the toothed wheel 113. This latter thusturns about an angle equal to that of the rotor of the stage 8,.

The supply of the fluid under pressure from another stage causes therotation of the toothed wheel to be added to the preceding one.

The return to the initial position may be effected in two fashions:firstly, if the group of the bores 111a,

1 11b, etc. are connected to the discharge piping whilst injecting thefluid under pressure by the bore 112, all the stages simultaneously takeup the position shown in FIG. 5; secondly, in normal operation, thepressure in the bore 112 lies between the pressure of the source andthat of a fluid reservoir and it is thus possible to obtain a return tothe initial position, stage by stage. For this purpose, it is sufficientto connect the bore 111 of each stage to the reservoir.

Due to this construction, it will be found to be possible to cause apredetermined position of the toothed wheel 113 to correspond to eachstate" of the group of stages, each stage possessing two states definedby the direction in which the rotor is stopped on its stator.

It will also be observed that in the case where the angular travel ofone stage is insufficient, two or more stages may be coupled together inparallel in a manner similar to that described above with reference toFIGS. 1, 2 and 3.

When the multi-stage rotary jack is utilized for moving a heavy mass, itmay be necessary to use shock absorbers to avoid shocks at thetermination of the travel.

These shock absorbers may be of any desired kind, for example, utilizingsprings or having resilient or pneumatic abutments.

Advantageously, they may have a construction identical to that of thejacks hereinabove described, interposed at any desired points of thechain, but perma-.

nently supplied in such a fashion that they shall be stopped in thedirection opposite to the control. To this end, it is preferred toprovide two shock absorbers having opposed actions.

If, for example, it be supposed that the stage B, is a shock-absorbingstage, its bore lllb may be permanently supplied, thus maintaining theabutments 103 touching the vanes 102a in the direction of the arrow F,.Preferably, in this case, a counter-pressure, less than that of thesupply pressure of the bore 111b, is maintained in the central channel112, for example, by a discharge valve adjusted to a convenient value.

Such a stage B, thus constituted as a shock absorber, allows the shocksto be limited when the wheel 113 is moved in the direction opposite tothat of arrow F,. At the moment of shock, the abutments 103 can slightlyelongate the vanes 102a whilst driving back the feed fluid into the borelllb. Thus a certain energy due to the inertia of the members inmovement may be dissipated by the alternate flows passing through thebores lllb and the bore 112 which are provided with discharge valveswhich are conveniently adjusted.

As has been indicated, it will be preferable to provide a secondshock-absorbing stage analogous to that which has been described but itssupplies are reversed in such a manner that, in the absence of shocks,the abutments 103 touch the vanes 102 in the direction opposite to thatof the arrow F,. The second shockabsorbing stage thus allows shocks tobe avoided when the wheel 113 is driven in the direction of the arrow FIt will be well understood that the invention may be applied to manyfields and is not limited by the embodiments described and shown but, onthe contrary, embraces all modifications thereof.

What is claimed is:

l. A rotaryjack, comprising:

a shaft; and

a plurality of actuating stages, including two end stages and at leastone intermediate stage positioned coaxially around said shaft andaligned with each other, each stage comprising a casing and a sleevewithin the casing, said casing including a rotational restraining means,said sleeve including a vane, the casing and the sleeve being mountedcoaxially around said shaft for relative rotational movement withrespect to each other, said vane and rotational restraining meanscooperating with each other to limit the relative rotational movement ofsaid casing and sleeve, one of said casing and sleeve defining a rotorand the other a stator, the rotor of one stage being drivingly connectedto the stator of one of its contiguous stages, the stator and rotor ofsaid at least one intermediate stage being idly mounted on said shaftand one of said rotor and said stator of one of the end stages beingconnected to the shaft.

2. A rotary jack as defined in claim 1 wherein the sleeve and casing ofeach stage define at least one chamber and said shaft has at least oneconduit leading into the interior of said at least one chamber.

3. A rotary jack as defined in claim 2 wherein the shaft has as manyconduits as there are independent stages, each conduit being associatedwith a chamber of at least one of said stages.

4. A rotary jack as defined in claim 1 wherein said shaft is fixedlymounted.

5. A rotary jack as defined in claim 1 wherein a chamber of at least onestage is a shock absorber and is permanently connected to a conduit forcarrying fluid under pressure.

6. The rotary jack as defined in claim 1 wherein the casing of eachstage is a rotor and the sleeve of each stage is a stator.

7. A rotary jack as defined in claim 1 wherein the casing of each stageis a stator and the sleeve of each stage is a rotor.

8. The rotary jack as defined in claim 1 wherein said shaft is rotatablymounted,

Reconsideration and allowance of this application are requested.

1. A rotary jack, comprising: a shaft; and a plurality of actuatingstages, including two end stages and at least one intermediate stagepositioned coaxially around said shaft and aligned with each other, eachstage comprising a casing and a sleeve within the casing, said casingincluding a rotational restraining means, said sleeve including a vane,the casing and the sleeve being mounted coaxially around said shaft forrelative rotational movement with respect to each other, said vane androtational restraining means cooperating with each other to limit therelative rotational movement of said casing and sleeve, one of saidcasing and sleeve defining a rotor and the other a stator, the rotor ofone stage being drivingly connected to the stator of one of itscontiguous stages, the stator and rotor of said at least oneintermediate stage being idly mounted on said shaft and one of saidrotor and said stator of one of the end stages being connected to theshaft.
 2. A rotary Jack as defined in claim 1 wherein the sleeve andcasing of each stage define at least one chamber and said shaft has atleast one conduit leading into the interior of said at least onechamber.
 3. A rotary jack as defined in claim 2 wherein the shaft has asmany conduits as there are independent stages, each conduit beingassociated with a chamber of at least one of said stages.
 4. A rotaryjack as defined in claim 1 wherein said shaft is fixedly mounted.
 5. Arotary jack as defined in claim 1 wherein a chamber of at least onestage is a shock absorber and is permanently connected to a conduit forcarrying fluid under pressure.
 6. The rotary jack as defined in claim 1wherein the casing of each stage is a rotor and the sleeve of each stageis a stator.
 7. A rotary jack as defined in claim 1 wherein the casingof each stage is a stator and the sleeve of each stage is a rotor. 8.The rotary jack as defined in claim 1 wherein said shaft is rotatablymounted. Reconsideration and allowance of this application arerequested.